Steam boiler refers to the industrial boiler that heats water to a certain parameter and produces high temperature steam, the water is heated into steam in the boiler barrel, and the fire emits heat in the furnace, which is the principle of the steam boiler. Steam boiler belongs to special equipment, the design, processing, manufacturing, installation and use of the boiler must accept the supervision of the technical supervision department, the user can use the steam boiler only by obtaining the boiler use certificate. Steam boiler according to the fuel (electricity, oil, gas) can be divided into electric steam boiler, oil steam boiler, gas steam boiler three kinds; According to the structure, it can be divided into vertical steam boilers and horizontal steam boilers, small and medium-sized steam boilers are mostly single and double return vertical structures, and large steam boilers are mostly three-return horizontal structures.